I currently have an a14 and am wondering about the boring/stroking that others have done. i want to keep the engine block as its registered to the car. i can get my hands on an a 15 crank, whats a nice 'easy' setup with an a15 crank, what rods and what pistons have people used.

i'm not keen on spending millions, and don't want massive compression its my daily but i'm interested in boring it out as the bores are not honed really nicely... i'm putting quad motorbike efi throttle bodies on and megasquirting it too (aren't we all!)

a common upgrade for the a15 is a 79mm (80thou over) mazda flatop piston, i have these in my race coupe. but dont know about the a14 bore size.
as for stroking maybe offset grinding the crank. ive worked to do both of those to an a15 would take it out to 1734ccs but thats only a theory. check the wiki im sure that there is something in there.
cheers kurt

hi kurt, thanks for that! i don't want to stroke it necessarily, just thought that using an a15 crank would have a longer stroke. the mazda pistons, what are they from and do they go on a14 rods?

Hey Lags,

A little off topic BUT.... If you go the A15 crank, would you part with the A14 crank?

Chris

EDIT: I think dattoman_1000 had Mazda pistons in his race engine, but that might have changed by now. Perhaps ask him for some help?

Here is what I THINK he said

B6 1.6ltr Mazda has 78mm Bore. The pin height is different though so you may need to do some milling? Unsure of the exact figures (well I can't remember, read it somewhere).

Hi LAGWAGON.
Just something else.
When the motorbike quad throttlebodies have been setup, will you please post pics.
I am also in the process of trying this but my main concern is how to setup the computer unit to know when to squirt the injectors. As we know the timing will have to be perfect to do it when the valve is open.
Sorry for going off topic.
PM Dodgeman. I know he is the A series expert and think he will be able to answer your questions.

Lagwagon, the difference between the
A14 & A15 is the crank,the A15 has a 5 mm longer stroke. The con rods are the same, so the difference in height is in the gudgeon pin position in the piston. Using the A15 crank with A14 rods & 76 mm(stock bore) A15 pistons will give you a capacity of 1488 cc's, identical to the A15. You can then get 76.5 mm pistons or 77 mm pistons as a stock replacement to allow you to clean up the bore. Being such a small overbore you shouldn't have too much troubles with the compression.78 or 79 mm pistons are available,usually they are for a Mazda engine, & i think you have to bore out the gudgeon pin holes to suit the Nissan Gudgeon. My suggestion would be to get some 76.5 mm pistons from a Nissan dealer & get the block bored to suit. You then have 2 more overbore sizes left in the block, so you dont have to throw it away when it wears out.

hi lagwagon
the deck hight on a15 & a14 are the same u fit the a15 crank with a14 rods & a15 acl pistons 1mm oversize =1530 cc this will work ok with a high comp head about 29cc = about 9 to 1 comp . low comp a14 head is h72 or h75 but you can mill up to about 2 mm of to get comp up
ps a14 & a15 rods are the same . a15 pistons are 2.5mm lower but look out for crank clerance to block & oil pump
i am 97.8% on this but not 100%
hope this helps

edit get a cam to go with throttle bodies but if you mill the head look out for valve hitting pistons . (get a street cam )
or you will need more comp

i hope my spelling is ok

Oops, it seems we have more A series experts than I thought.

thats ok 1200gxman more backup is good

its all in the crank lags, but instead of the mazduh bp 1.6 pistons, why not go the e15 pulsar turbo pistons, cause we can all see what will happen after efi.... turbo